PROJECT SUMMARY Epidemiologic studies report that cracked teeth are the third most common cause for tooth loss in industrialized countries. All cracks are colonized by bacteria, which have the potential to cause pulpal and periapical disease. Pain associated with these diseases is intense and is the most common reason for seeking emergency dental care. Cracked teeth present a complex, diagnostic dilemma since symptoms associated with cracked teeth are often discontinuous with periods of remission. If left undetected, cracks continue to progress and ultimately result in tooth loss. Available clinical tools used to detect cracks have limitations and often cannot determine the extent of the crack. To address this we propose to develop an open-source software solution based on 3D Isotropic Steerable Wavelets that will accurately detect the presence and quantify cracks in any location and orientation. The work proposed will a) create a novel image analysis method and software solution for 3D tracing and 3D visualization of tooth cracks using high resolution CBCT and b) perform validation of the 3D crack detection biomarkers on extracted human teeth. The work proposed addresses a significant need for quantitative, reproducible and evidence-based techniques to detect and localize cracks on teeth. Successful completion of this Phase I proposal will result in a Phase II SBIR proposal focused on the clinical validation of the proposed methodology on different types of cracks in-vivo. This will ultimately lead to a better understanding of this pathology and thus to better preventive strategies and improved tracking of the progression of cracks in patients.